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. 1989 Mar;410:107–122. doi: 10.1113/jphysiol.1989.sp017523

Galanin-induced hyperpolarization and decreased membrane excitability of neurones in mudpuppy cardiac ganglia.

L M Konopka 1, T W McKeon 1, R L Parsons 1
PMCID: PMC1190469  PMID: 2477525

Abstract

1. Membrane hyperpolarization and decreased excitability produced by galanin were investigated in vitro on parasympathetic postganglionic neurones in the cardiac ganglion of the mudpuppy, Necturus maculosus. 2. Galanin produced a slowly developing hyperpolarization which, in 2.5 mM-KCl, reversed at -105.4 +/- 2.7 mV. The reversal potential was shifted by 38.7 +/- 4.9 mV following a fourfold elevation of the extracellular potassium concentration. 3. Galanin inhibited action potential firing in spontaneously active neurones and decreased the number of spikes in a train produced by long (500-680 ms) depolarizing current pulses. Both effects were independent of the galanin-induced hyperpolarization. 4. Galanin increased the threshold for spike generation, prolonged the spike hyperpolarizing after-potential and decreased the maximum rate of rise, amplitude and maximum rate of fall of the sodium spike. These effects occurred independently of the galanin-induced hyperpolarization. 5. Galanin decreased the amplitude and duration of TTX-insensitive spikes initiated in cells maintained in a solution containing 9 mM-calcium, 20 mM-TEA and 1.5 microM-TTX. 6. These results suggest that a galanin-like peptide may act as an inhibitory transmitter in the mudpuppy cardiac ganglion.

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Selected References

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  1. Adams P. R., Brown D. A., Constanti A. Pharmacological inhibition of the M-current. J Physiol. 1982 Nov;332:223–262. doi: 10.1113/jphysiol.1982.sp014411. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Adams P. R., Brown D. A. Luteinizing hormone-releasing factor and muscarinic agonists act on the same voltage-sensitive K+-current in bullfrog sympathetic neurones. Br J Pharmacol. 1980 Mar;68(3):353–355. doi: 10.1111/j.1476-5381.1980.tb14547.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Adams P. R., Constanti A., Brown D. A., Clark R. B. Intracellular Ca2+ activates a fast voltage-sensitive K+ current in vertebrate sympathetic neurones. Nature. 1982 Apr 22;296(5859):746–749. doi: 10.1038/296746a0. [DOI] [PubMed] [Google Scholar]
  4. Akasu T., Nishimura T., Koketsu K. Modulation of action potential during the late slow excitatory postsynaptic potential in bullfrog sympathetic ganglia. Brain Res. 1983 Dec 5;280(2):349–354. doi: 10.1016/0006-8993(83)90066-5. [DOI] [PubMed] [Google Scholar]
  5. Akasu T., Nishimura T., Koketsu K. Substance P inhibits the action potentials in bullfrog sympathetic ganglion cells. Neurosci Lett. 1983 Oct 31;41(1-2):161–166. doi: 10.1016/0304-3940(83)90240-9. [DOI] [PubMed] [Google Scholar]
  6. Bishop A. E., Polak J. M., Bauer F. E., Christofides N. D., Carlei F., Bloom S. R. Occurrence and distribution of a newly discovered peptide, galanin, in the mammalian enteric nervous system. Gut. 1986 Jul;27(7):849–857. doi: 10.1136/gut.27.7.849. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Breitwieser G. E., Szabo G. Uncoupling of cardiac muscarinic and beta-adrenergic receptors from ion channels by a guanine nucleotide analogue. Nature. 1985 Oct 10;317(6037):538–540. doi: 10.1038/317538a0. [DOI] [PubMed] [Google Scholar]
  8. Ekblad E., Rökaeus A., Håkanson R., Sundler F. Galanin nerve fibers in the rat gut: distribution, origin and projections. Neuroscience. 1985 Oct;16(2):355–363. doi: 10.1016/0306-4522(85)90008-9. [DOI] [PubMed] [Google Scholar]
  9. Hartzell H. C., Kuffler S. W., Stickgold R., Yoshikami D. Synaptic excitation and inhibition resulting from direct action of acetylcholine on two types of chemoreceptors on individual amphibian parasympathetic neurones. J Physiol. 1977 Oct;271(3):817–846. doi: 10.1113/jphysiol.1977.sp012027. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Jan L. Y., Jan Y. N. Peptidergic transmission in sympathetic ganglia of the frog. J Physiol. 1982 Jun;327:219–246. doi: 10.1113/jphysiol.1982.sp014228. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Jones S. W. Muscarinic and peptidergic excitation of bull-frog sympathetic neurones. J Physiol. 1985 Sep;366:63–87. doi: 10.1113/jphysiol.1985.sp015785. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. MacDermott A. B., Weight F. F. Action potential repolarization may involve a transient, Ca2+-sensitive outward current in a vertebrate neurone. Nature. 1982 Nov 11;300(5888):185–188. doi: 10.1038/300185a0. [DOI] [PubMed] [Google Scholar]
  13. McMahan U. J., Purves D. Visual identification of two kinds of nerve cells and their synaptic contacts in a living autonomic ganglion of the mudpuppy (Necturus maculosus). J Physiol. 1976 Jan;254(2):405–425. doi: 10.1113/jphysiol.1976.sp011238. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Melander T., Hökfelt T., Rökaeus A., Fahrenkrug J., Tatemoto K., Mutt V. Distribution of galanin-like immunoreactivity in the gastro-intestinal tract of several mammalian species. Cell Tissue Res. 1985;239(2):253–270. doi: 10.1007/BF00218003. [DOI] [PubMed] [Google Scholar]
  15. Neel D. S., Parsons R. L. Catecholamine, serotonin, and substance P-like peptide containing intrinsic neurons in the mudpuppy parasympathetic cardiac ganglion. J Neurosci. 1986 Jul;6(7):1970–1975. doi: 10.1523/JNEUROSCI.06-07-01970.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Palmer J. M., Schemann M., Tamura K., Wood J. D. Galanin mimics slow synaptic inhibition in myenteric neurons. Eur J Pharmacol. 1986 May 27;124(3):379–380. doi: 10.1016/0014-2999(86)90246-3. [DOI] [PubMed] [Google Scholar]
  17. Parsons R. L., Neel D. S., McKeon T. W., Carraway R. E. Organization of a vertebrate cardiac ganglion: a correlated biochemical and histochemical study. J Neurosci. 1987 Mar;7(3):837–846. doi: 10.1523/JNEUROSCI.07-03-00837.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Pfaffinger P. J., Martin J. M., Hunter D. D., Nathanson N. M., Hille B. GTP-binding proteins couple cardiac muscarinic receptors to a K channel. Nature. 1985 Oct 10;317(6037):536–538. doi: 10.1038/317536a0. [DOI] [PubMed] [Google Scholar]
  19. Tamura K., Palmer J. M., Wood J. D. Galanin suppresses nicotinic synaptic transmission in the myenteric plexus of guinea-pig small intestine. Eur J Pharmacol. 1987 Apr 29;136(3):445–446. doi: 10.1016/0014-2999(87)90323-2. [DOI] [PubMed] [Google Scholar]
  20. Yau W. M., Dorsett J. A., Youther M. L. Evidence for galanin as an inhibitory neuropeptide on myenteric cholinergic neurons in the guinea pig small intestine. Neurosci Lett. 1986 Dec 23;72(3):305–308. doi: 10.1016/0304-3940(86)90531-8. [DOI] [PubMed] [Google Scholar]

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